Three problems related to engine and engine cooling have been reported for the 2004 Mazda MPV. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Mazda MPV based on all problems reported for the 2004 MPV.
My 2004 Mazda Mpv suffered the same problem as many other consumers. On two different occasions I had to replace all of the coils and plugs on my vehicle. The first instance was just after the warranty expired and involved one of the rear coils but the said I should replace all three rear coils. The second incident occurred two months later to the front coil and I replaced all of those - total cost $900. I complained to Mazda but they wouldn't do anything for me. This should be recalled and owners compensated.
The engine coils have failed 4 times since we have owned the vehicle. Last night while traveling on the interstate in the rain, key words, in the rain it started again. I am sure at least one if not two coils went this time. Just had a coil and all the boots that are suppose to protect the coils and keep the moisture out replaced in February, 2012. It always happens when it rains. Mazda is well aware of the situation and has done nothing to fix this issue except to stop using this system and start making their cars differently. But what about the people who own the older models? this is a dangerous situation as I was on the highway, at night, and it was pouring down rain and the van starts slowing down and sputtering along, with traffic traveling behind me. This should be a recall issue as it is a known problem and it is because of a manufacturing defect not anything that owners can avoid.
2004 Mazda Mpv engine completely and suddenly dies when driving - usually when pressing the accelerator pedal as the engine is decelerating. Drove car to shoulder, placed in neutral to restart. Appears to be the idle control valve (madza forum sites report numerous similar events).